As stated in the title, if you trash a page that has children, then restore that page (which will naturally restore its children), then the child pages will not go back to their previous status of 1, but instead 8173.
Visually, those child pages look fine in the page tree (they look like regular published pages), but any page reference fields (like a select dropdown for example), will no longer be able to select those pages. Not even saving those child pages in the editor takes it back to 1.
This tripped me up, so I went into the 'pages' database table and discovered they were in status 8173. Forcing it to 1 fixed the issue.
Tested with PW 3.0.245.